[PATCH] D14252: [AsmParser] Allow tokens to be put back in to the token stream.

[Colin LeMahieu via llvm-commits]

colinl added a comment.

Although a datastructure like a deque or a ring buffer would more directly represent what we're trying to do, a SmallVector was chosen because some backends do the following sequence:

AsmToken const &Token = Lexer.getTok();
useToken(Token);
Lexer.Lex();
useToken(Token);

Since the number of tokens in the buffer is going to be small, usually 1, a SmallVector with pushing to head should be fine.

There should be no functional change.

I noticed some backends have copy/pasted the built in expression parser for similar reasons as above, they could possibly make use of this change.


Repository:
  rL LLVM

http://reviews.llvm.org/D14252